German newspaper Der Spiegel has released excerpts of a previously unpublished interview National Security Agency leaker Edward Snowden conducted prior to revealing himself publicly. The interview was conducted over encrypted emails starting in mid-May between an anonymous Snowden, internet security activist Jacob Appelbaum, and documentarian Laura Poitras, who helped write some of the first reports based on documents leaked by Snowden. The questions were generated by Appelbaum after Poitras told him she wanted him to help assess the legitimacy of someone who contacted her claiming to be from the NSA.

Along with providing a window into how Snowden communicated with activists prior to releasing his documents to the press, the interview sheds some light on Snowden's claims about the NSA's surveillance capabilities.

In the interview, Snowden says the NSA works with foreign governments "all the time" and that the agency worked with Israel as a co-author of the Stuxnet virus that targeted Iranian nuclear facilities. He also discussed the agency's storage facilities and said the NSA currently can only hold small amounts of flagged data in perpetuity, but is hoping to reach a point where metadata on online communications is "permanently stored."